The present invention relates generally to methods for bonding dissimilar materials, and more particularly to a method for bonding plastic to metal utilizing a chemical milling process.
In certain fabrication processes wherein a plastic member is placed in contact with a metallic member, injection molding or similar processes have been used to form the plastic member onto the metallic member. If substantial adhesion between the plastic and metallic members is desired, the metallic member may first be conditioned by such processes as roughening or knurling the surface interfacing the plastic member, or flame or plasma spraying a porous coating thereon, or attaching fastening objects thereto. Certain end uses for products formed of a plastic member bonded to a metallic member may, however, require a reproducible and substantially stronger bond at the interface than is obtainable using adhesives and conventional surface preparation techniques.
The present invention substantially solves or reduces in critical importance deficiencies in the prior art as just described by providing a method for bonding plastic to a metallic member. In accordance with teachings of the invention, cavities are formed in the surface of the metallic member by etching using masking and etching techniques and allowing the etchant to undercut the surface to provide an interlock with a plastic member subsequently applied to the metallic surface by spraying, injection molding or the like or by heating/pressing the plastic member to the metallic member.
It is therefore a principal object of the invention to provide a method for bonding plastic to metal.
It is a further object of the invention to provide a method for bonding dissimilar materials, particularly plastic to metal, utilizing masking and etching techniques.
These and other objects of the invention will become apparent as the detailed description of representative embodiments proceeds.